The present invention relates generally to cylinder head assemblies for internal combustion engines, and more particularly to a cylinder head assembly housing a camshaft position sensor to detect an angular position (a rotation angle) of a camshaft of an internal combustion engine.
Internal combustion engines generally include a camshaft position sensor to detect an angular position (a rotation angle) of a camshaft to open and close an intake valve or an exhaust valve. The camshaft position sensor senses a signal plate attached to a rear end portion of the associated camshaft. More specifically, located outward in a radial direction from the signal plate, the camshaft position sensor detects projections or grooves formed in the outer peripheral portion of the signal plate. In general, the camshaft position sensor is attached to a sensor boss formed in a cylinder head or a cylinder head cover covering a top opening of the cylinder head. Japanese Patent No. 3431505 shows such a structure in which the sensor boss for the camshaft position sensor is formed in a cylinder head.